Estimation of Velocities in an Urban Segment through CTM model

Abstract

Abstract-Because of its close relationship to density and flow, velocity play a key role in prediction of traffic parameters with the purpose of use in real-time traffic control. In this paper is proposed a procedure of estimation of velocities through a macroscopic model that originates from LWR (Lighthill-Whitham-Richards) model called Cell Transmission Model. Beside the possibility to update the densities of cells through time step, the CTM model enables the estimation of evolution of the velocities thanks to some known models that describe these relationships. A case study in an urban segment is treated in order to estimate velocities. Validation of these velocity values is done by comparing the inter cell flows from CTM (Cell Transmission Models) model and flows as function of updates velocities. Keywords –Cell, density, inter cell flow, outflow, velocity, model hypothesis